Stain and soil repellent composition

ABSTRACT

The invention relates to a stain and soil repellent composition for a carpet, especially from polyamide, wherein a first condensation product of hydroxyaromatic compounds and formaldehyde, which is free of sulphonic acid- and carboxyl-groups; and a second condensation product of hydroxyaromatic compounds and formaldehyde, which is at least partially sulphonated is applied to the carpet in a foam application process together with a fluorocarbon compound.

BACKGROUND OF THE INVENTION

The present invention relates to a stain and soil repellent composition for carpets. The invention especially relates to a stain and soil repellent composition for carpets made from polyamide, wool and their mixtures.

During the production of carpets, various stain and soil repellent chemicals are often applied. The application is typically carried out in two steps with the application of the stain repellent being first, followed by a treatment with a fluorocarbon compound.

A stain repellent can be applied to a carpet in a continuous or discontinuous process, in which between 3 and 7 weight-% of the stain repellent relative to the pile weight (the weight of the utilized fiber) is used. It is also known that considerably higher concentrations, for example up to 10 weight %, can be utilized.

In the discontinuous application, a separate treatment bath is utilized after the dyeing step, in which the stain repellent is applied to the carpet at a pH between 2.5 and 7.

In the continuous application, the stain repellent is applied to the carpet with suitable devices, such as a waterfall applicator, immersion tank and Fluidyer® apparatus.

After the application of the stain repellent, a treatment with a fluorocarbon compound follows as the last finishing step, for example with a desired concentration of from 1.0 to 1.6 weight-% of fluorocarbon relative to the pile weight of the carpet. The application of the fluorocarbon compound typically precedes the dryer of the continuous dye unit or is prior to the coating oven. The simplest procedure is a spray application which is carried out with a suitable spray device. The fluorocarbon compound is applied as an aqueous solution to a dry or lightly moistened carpet. The most often-used application method is a foam application. With this system, a highly concentrated solution of the fluorocarbon compound can be applied to the carpet as a foam with minimal wetness. For the foam creation, special foaming aids are added to the fluorocarbon compounds, which then degrade at the selected drying temperatures, and the fluorocarbon compound remains on the fiber and bonds to it.

The two-step process is time consuming, relatively high cost, and resource intensive. Thus, the application of the stain repellent together with the fluorocarbon in a single step is advocated.

For example US2003/0204015 A1 reveals that a mixture containing a sulphonated condensation product of phenol and formaldehyde and other compounds as stain repellent, and fluorocarbon compounds can be applied to the fibers.

The application of stain repellent based on resole together with fluorinated, oil, water and/or soil repellent substances on a polyamide substrate is disclosed in U.S. Pat. No. 5,447,755.

However, there is still a need for improved stain and soil repellent compositions for one-step application. Therefore, the task of the present invention is to provide an improved stain and soil repellent composition compared to the current state of technology.

This task was achieved according to the invention by using a combination of two different stain repellents together with a fluorocarbon compound to impart desirable stain and soil repellent properties to carpets.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is a stain and soil repellent composition which encompasses the following components:

-   -   (a) a first condensation product of hydroxyaromatic compounds         with formaldehyde, which is free of sulphonic acid and         carboxylic groups,     -   (b) a second condensation product of hydroxyaromatic compounds         with formaldehyde, which is at least partially sulphonated,     -   (c) at least one fluorocarbon compound,     -   (d) at least one foaming agent, in case that (c) has no foam         building properties,     -   (e) water,     -   (f) if required at least one plasticizer,     -   (g) if required at least one fluorine containing surfactant,     -   (h) if required at least one blocked isocyanate group containing         polymer or oligomer, and     -   (i) if required additional additives.

According to the invention, hydroxyaromatic compounds are compounds which have at least one, preferably one or two, aromatic nucleus, and at least one hydroxyl group directly bound to the nucleus or one of the nuclei. Other substituents can be bound to the nucleus besides the hydroxyl group, for example halogens, or sulfonic acid groups. Ring systems with 6 to 12 carbon atoms are preferred as the aromatic nucleus, for example phenyl or naphthyl radicals with an OH group in the 1, 2, or 3 position. Especially suited are substituted and non-substituted phenol, 1-naphthol, and 2-naphthol. Hydroxyaromatic compounds with more than one hydroxyl group at the nucleus are also suitable, for example di-hydroxyaromatic compounds such as resorcinol and catechol, or tri-hydroxyaromatic compounds such as pyrogallol (1,2,3-tri-hydroxybenzol). Several aromatic nuclei can also be covalently bonded over a functional group, for example a sulfone group.

The condensation products of the hydroxyl aromatic compounds with formaldehyde according to the invention are inherently easy to make and are known to those skilled in the art. For example, novolak with linear chains can be obtained from an acid catalyzed reaction of excess phenol with formaldehyde, in which the phenol units are bonded with methylene bridges. Utilizing a basic catalyst and excess formaldehyde, phenol and formaldehyde are condensed to resoles. To obtain condensation products with sulfone groups at the aromatic nucleus, the aromatic adducts either already have sulfonic acid groups or they can be attached after a typical condensation, for example, through a reaction with sulfur trioxide, chlorosulphonic acid, or amidosulphonic acid. If the adducts already contain sulphonic acid groups, a condensation reaction of the OH-groups of the sulphonic acid group can occur, so that the end products of the condensation reaction do not have any free sulphonic acid groups and, therefore, can be utilized as a condensation product according to component (a) of the present invention.

Commercial condensation products without sulphonic acid and carboxyl groups can be obtained, for example, under the name ZELAN® 8236 from DuPont, Wilmington, Del., USA. ZELAN® 8236 is a base catalyzed condensation product of 4,4′bis(hydroxyphenyl) sulfone and formaldehyde. Condensation products with sulphonic acid groups are commercially obtainable, for example, from Zschimmer & Schwarz Mohsdorf GmbH & Co., Mohsdorf, Germany under the name Zetesal NT and from CHT R. Beitlich GmbH, Tubinen, Germany under the name Rewin KBL or Rewin KF as well as Tubicoat KF.

The essential element of the present invention is that at least one condensation product, which is free of sulphonic acid and carboxyl groups, and at least one condensation product, which is at least partially sulphonated are used together. This combination enables the application at neutral pH and yields unexpectedly improved stain repellency, as shown in the examples below.

The compositions according to the invention contain, furthermore, at least one fluorocarbon compound (c), and, if required, at least one foaming aid (d). If a commercial product is being used for the component (c), then the foaming aid may already be contained in the commercial composition, so that it does not need to be added additionally to the composition. Based on the possible inherent foam building properties of the utilized components, it is possible, that by stirring alone, the compositions can create foam, and the addition of a foaming aid (d) is, therefore, not required. However, it can be helpful to add further foaming aids (d) to the stain and soil repellent composition of this invention despite inherent foam building properties of (c).

The fluorocarbon compound of the component (c) is utilized together with the condensation products of the components (a) and (b) to impart oil, water and soil repellent properties to the substrate. Anionic, cationic or non-ionic as well as amphoteric fluorine compounds are in principle used as fluorocarbon compounds, which are also commercially available. For example, fluorine containing polyacrylates (U.S. Pat. No. 3,574,791 and U.S. Pat. No. 4,147,851) and fluorine containing urethanes (U.S. Pat. No. 3,398,182 and US 2003/0204015 A1) can be utilized. Suitable fluorocarbon compounds can be obtained under the collective name Zonyl® Carpet Protector from DuPont. These include, for example, Zonyl® 19087, Zonyl® 9535, Zonyl® 555 and Zonyl® 5180. An example of a commercial anionic fluorocarbon compound is Zonyl® 9087 (DuPont). The production of such fluorocarbon compounds is known to those skilled in the art and can be accomplished, for example, by attaching linear fluorinated chains called fluorotelomers to organic polymers. For example, tetrafluoroethylene (TFE) is reacted to form a fluorocarbon compound in a telomerization process. Fluorocarbon compounds can be subdivided basically into three molecular regions. Perfluoroalkyl groups are responsible for soil repellency as well as hydrophobation and oleophobation. A spacer gives the required molecular flexibility, so that the fluorocarbon compound is soluble and/or emulsifiable. An anchoring and/or adhesive group ensures the permanency of the fluorocarbon compounds. Preferred anchoring groups are those based on urethane.

Commercial foam builders such as alkyl amine oxides, for example Laviron 118SK, Cognis Germany GmbH & Co. KG, Dusseldorf, Germany, can be utilized as additional foaming aids for component (d). Furthermore, alpha-olefin sulfonate, such as Reworyl AOS 38 or Sulfrarnin AOS 38 (Goldschmidt GmbU, Germany); and modified lauryl sulfate, such as Tubicoat ELS (CIJT R. Breitlich GmbH, Germany) and Baygard Foamer (Lanxess Europe (GmbH & Co KG, Germany) are suitable foam builders.

Foaming aids are being utilized for foam improvement methods by adding them directly to the finishing agent, which is to be foamed.

The stain and soil repellent compositions of the present invention are prepared in water (e) as solvent.

At least one plasticizer (f) can be present in the compositions according to the invention. Polysiloxane compounds, such as amino functional polydimethylsiloxane; fatty acid condensation products, such as condensation products of hydrated tallow with 2-[2-aminoethyl)-amino]ethanol; and acetate salt (CAS No. 68425-52-5) or acryl compounds such as bis[acryloxyethyl]-hydroxymethyl ammonium methyl sulfate (CAS No. 93334-15-7) are suitable in principle as plasticizers. A plasticizer from the above mentioned compounds or a mixture of them can be included in the composition according to the invention. Suitable plasticizers are commercially available, for example, Finistrol AFN (fatty acid condensation product) of Thor, Speyer, Germany, and Megasoft JET of Ciba Specialty Chemicals; Perrustol CCA (fatty acid condensation product) of Rudolf GmbH & Co. KG, Geretsried, Germany; Raniesoft TS 20 (fatty acid condensation product) of Ranie Chemie, Wiehl, Germany; Softycon N (fatty acid condensation product) Textilcolor AG, Sevelen, Switzerland; and Zefasoft NI (fatty acid condensation product) of Zschirnmer & Schwarz Mohsdorf GmbH & Co. IKG, Mohsdorf, Germany.

At least one fluorotenside (g) can be included in the composition according to the invention. Better penetration to a carpet with the stain and soil repellent according to the invention is achieved with addition of the fluorotenside. Suitable fluorotensides are obtained, for example, from DuPont Specialty Chemicals under the name Zonyl®. In principle, anionic, cationic, non-ionic or amphoteric fluorotensides are useful in practicing the invention. Zonyl® FSA, FSP, FSE, UR, FSJ, FSN, FSN-100, FSO, FSO-100, FSD as well as TBS are especially suitable. In general, compounds with a hydrophobic portion of the formula C_(n)F_(2n+1) and a hydrophilic portion, for example, containing carboxylic acid or carboxylic acid ester groups, phosphate or phosphoric acid ester groups, ether groups, or sulphonic acid groups are suitable. Especially suitable are the compounds with the following formulas, whereby R_(f) represents F(CF₂CF₂)₂ where a=2 to 10, preferably 3 to 8:

R_(f)CH₂CH₂SCH₂CH₂CO₂Li,

(R_(f)CH₂CH₂O)P(O)(ONH₄)₂,

(R_(f)CH₂CH₂O)₂P(O)(ONH₄),

(R_(f)CH₂CH₂O)P(O)OH₂,

(R_(f)CH₂CO₂O)₂P(O)OH,

R_(f)CH₂CH₂O(CH₂CH₂O)_(x)H,

R_(f)CH₂CH₂SO₃H.

whereby x can take the value from 1 to 20, preferably from 1 to 10.

The compositions according to the invention can contain only a special fluorotenside or a mixture of different fluorotensides alone or in a mixture with other non-fluorine containing tensides. Non-fluorine containing tensides contain a hydrophobic portion, for example, C₂H_(2n+1) with n=1 to 20.

Furthermore, at least one blocked isocyanate group containing polymer or oligomer (h) can be used. Preferred are polyisoyanates. Gard WEB (Rudolf GmbH & Co. KG, Germany) and Hydrophobol XAN (Ciba, Switzerland) are commercial products, which can be utilized as components (h) in the context of the present invention. The polymers or oligomers of these components contain at least one or more than one blocked isocyanate group, for example 2, 3, 4, 5 or more.

The compositions according to the invention can further contain customary additives (i) to reduce the cost of the composition. For example, the following substances can be used as additives either alone or as mixtures: siloxane; acrylate and substituted acrylate polymers and copolymers; n-methylolacrylamide containing acrylate copolymers; urethane; condensate or precondensate of urea or melamine with formaldehyde; glyoxal resins; condensate of fatty acids with melamine or urea derivatives or with polyamides and their epichlorohydrin adducts; waxes; polyethylene; chlorinated polyethylene; alkene ketene dimers, esters and amides; glycols, such as diethylene glycol; and fatty acids and their derivative and salts, such as stearic acid or stearic acid sodium salt. Furthermore, pH regulators, for example, inorganic or organic acids and bases can be used. Also surface-active substances and/or dispersion agents can be used in the composition.

The components (a) are present in the composition for best results according to the invention at from 0.1 to 3 weight-%, preferably at from 0.2 to 0.5 weight-%, especially preferred at from 0.2 to 0.49 weight-%. Components (b) are present, for example, at from 0.1 to 3 weight-%, preferably at from 0.2 to 0.5 weight-%, especially preferred at from 0.2 to 0.49 weight-%. Components (c) are present, for example, at from 0.5 to 3.5 weight-%, preferably at from 0.7 to 1.7 weight-%, and especially preferred at from 0.7 to 1.69 weight-%. Components (d) are present for example, at from 0 to 5 weight-%, preferably at from 0.05 to 0.1 weight-%, and especially preferred at from 0.05 to 0.09 weight-%. Components (e) are present, for example, at from 71 to 99.3 weight-%, preferably at from 91.4 to 98.84 weight-%, and especially preferred at from 91.47 to 98.83 weight-%. Components (f) are present, for example, at from 0 to 2% weight-%, preferably at from 0.01 to 0.1 weight-%, and especially preferred at from 0.01 to 0.09 weight-%. Components (g) are present, for example, at from 0 to 0.5 weight-%, preferably at from 0 to 0.2 weight-%, and especially preferred at from 0.01 to 0.2 weight-%. Components (h) are present, for example, at from 0 to 2.0 weight-%, preferably at from 0 to 0.5 weight-%, and especially preferred at from 0 to 0.49 weight-%. Components (i) are present, for example, at from 0 to 10 weight-%, preferably at from 0 to 5 weight-%, and especially preferred at from 0 to 4.99 weight-%.

In contrast to the traditional stain and soil repellent compositions, the composition of the present invention is applied at a neutral pH1, for example, between 6 and 8, and preferably between 7 and 8. The pH results when all of the individual components are mixed together.

Components (b) alone can only be applied at an acidic pH-value, since this value is required so that they can react with the fibers and become effective. Components (a) alone, however, can be applied at neutral pH value and are effective at that range. A mixture of (a) and (b) according to the invention results in a composition with a neutral pH range. This has a great advantage, since the application of the composition according to the invention with the preferred application method, is the last step of the total process. No rinsing step with water needs to follow. If only components (b) were to be utilized, a (strong) acid would remain on the carpet, which would lead to fiber damage with time.

The alternative utilization of components (a) alone, according to the present invention, is not possible at a neutral pH value in the preferred foam application process, since (a) is not compatible with foaming agents. Only mixing of components (a) and (b) is surprisingly possible in the foam application procedure.

In the production of the compositions according to the invention, the stain repellents (a) and (b) are first mixed together then (f), and if required (g), (h) and (i) are added. At a later point in time, the mixture is stirred into water and subsequently mixed with the fluorocarbon compound (c) and if required with (d). If additional plasticizer (f) is used, then it is added preferably to the aqueous solution of (a), (b), and if required (g), (h) and (i) as well as (c) and (d). If larger quantities of the plasticizer, for example more than 2 parts (f), are added directly into the products (a), (b) or (c) and (d), (i.e., in concentrated, not water diluted form), then poorer results in terms of lower stain and soil repellancy are generally obtained.

The compositions of this invention can be offered and stored in different ways. On the one hand, all components (a) to (d) as well as if required (f) and/or (g) and/or (h) and/or (i) can be premixed, and the mixed composition can be conveniently stored in a suitable container. On the other hand, the individual components can be split into different containers and only added together just prior to or as part of the application.

For example, the condensation products (a) and (b) and if required (f) and/or (g) and/or (h) and/or (i) can be stored together in one container, and the components (c) and (d) can be stored separately from each other and separately from (a) and (b). It is also feasible to store mixtures of components (a) to (c) and if required (f) and/or (g) and/or (h) and/or (i) in one container and to store (d) isolated from the mixture. Every conceivable combination and division into individual containers is possible. It is preferred that the components (a), (b) and (f) as well as if required (g), (h) and (i) are mixed in one container and then offered in one container. Upon application, i.e., at the time of application, the mixture is then further mixed with component (c) where (d) may be added if required.

The compositions of this invention are suitable as a stain and soil repellent for carpets, for example, tufted carpets or woven carpets made from any conceivable polyamide, especially nylon 6 and nylon 6,6. They can be utilized as well for wool carpets or carpets made from a mixture of wool and nylon, especially in the ratio of 80:20.

The compositions are particularly useful in a process of imparting stain and soil repellent properties to a carpet them. In the process, a mixture of all components is applied to the carpet in a foam-co-application. The stain repellent components (a) and (b) are applied together with fluorocarbon compounds (c) and the other required components onto the carpet as foam and not in succession, as is often the case. The compositions according to the invention are applied at from 0.5 to 5 weight-%, and preferably at from 0.5 to 2 weight-% relative to the pile weight of the carpet.

The invention is explained with the following examples to a greater extent, without it being limited by them.

EXAMPLE AND COMPARISON EXAMPLE

Production of a stain repellent composition according to the invention: 0.25 weight-% Zelan® 8236 and 0.25 weight-% Rewin KF or Tubicoat KF were mixed with 99.5 weight-% water. Three parts by weight of this mixture were intensively mixed with a mixture consisting of 90 parts by weight of water and of 7 parts by weight of Zonyl® 9087. The pH of this mixture as measured was between 7 and 8.

Treatment of a carpet:

A cut pile nylon carpet (beige), 860 g/m² was treated one time (A) with 3 weight-% of the above described mixture in a foam co-application with a fluorocarbon compound, and (B) for comparison with a product which only contains a stain repellent, with sulphonic acid groups and a fluorocarbon compound. After drying, the stain repellent efficiency (24 hrs Kool-Aid test and 24 hrs. Coffee test), the water and oil repellency as well as light fastness (according to ISO 105-BO2), and resilience towards alkali cleaning products (WAQE-test) were tested. The results are summarized in the following table:

24 hrs WAQE TEST 24 hrs Kool- Coffee Water Oil Light sodium lauryl Aid Rinsed Cleaned Repellency Repellency Fastness Sulfate Scale 1-10 1-10 1-6 1-6 1-8 1-10 Aim >=9-10   >=8-9    >=8-9   >=3 >=4-5   >=6 (A) 10 9 3 2 5-6 9 (B)  9 7 3 2 5 —

Excellent results were obtained with the stain and soil repellent composition according to the invention as compared to a traditional stain and soil repellent composition which only contain one stain repellent with sulphonic acid groups. The stain repellent properties of a nylon carpet sample treated with a composition according to the invention corresponded to the upper level of the scale of desired values. 

1. A stain and soil repellent composition comprising: (a) 0.1 to 3% by weight of hydroxyaromatic compounds with formaldehyde, which is free of sulphonic acid and carboxylic groups; (b) 0.1 to 3% by weight of hydroxyaromatic compounds with formaldehyde, which is at least partially sulphonated; (c) 0.5 to 3.5% by weight of at least one fluorocarbon; (d) 0 to 5% by weight of at least one foaming agent; (e) 71 to 99.3% by weight of water; (f) 0 to 2% by weight of at least one plasticizer; (g) 0 to 0.5% by weight of at least one fluorine containing surfactant; and (h) 0 to 2% by weight of at least one blocked isocyanate group containing polymer or oligomer.
 2. A stain and soil repellent composition according to claim 1 comprising: (a) 0.2 to 0.5% by weight of hydroxyaromatic compounds with formaldehyde, which is free of sulphonic acid and carboxylic groups; (b) 0.2 to 0.5% by weight of hydroxyaromatic compounds with formaldehyde, which is at least partially sulphonated; (c) 0.7 to 1.7% by weight of at least one fluorocarbon; (d) 0.05 to 0.1% by weight of at least one foaming agent; (e) 91.4 to 98.84% by weight of water; (f) 0.01 to 0.1% by weight of at least one plasticizer; (g) 0 to 0.2% by weight of at least one fluorine containing surfactant; and (h) 0 to 0.5% by weight of at least one blocked isocyanate group containing polymer or oligomer.
 3. The stain and soil repellent composition, according to claim 1 or claim 2 wherein the pH of a mixture formed by mixing all of the components together is from 6 to
 8. 4. The stain and soil repellent composition of claims 3 wherein the pH of the mixture obtained by mixing all of the components together is from 7 to
 8. 5. The stain and soil repellent composition, according to the claim 1 or claim 2, wherein the hydroxyl aromatic compounds (a) and (b) are chosen from the group consisting of substituted and unsubstituted phenol, naphthol, resorcinol, catechol and pyrogallol.
 6. The stain and soil repellent composition, according to the claim 5, wherein the hydroxyl aromatic compounds (a) and (b) are chosen from the group consisting of phenol, naphthol, phenol substituted with at least one sulphonic acid group, and naphthol substituted with at least one sulphonic acid group.
 7. The stain and soil repellent composition, according to the claim 1 or claim 2, wherein the fluorocarbon (c) comprises perfluoro alkyl groups, a spacer, and an anchoring- and/or adhesive group based on urethane.
 8. The stain and soil repellent composition, according to the claim 1 or claim 2, wherein foaming agent (d) is an alkylaminoxide, an alphaolefin sulphonate or a modified lauryl sulfate.
 9. The stain and soil repellent composition, according to the claim 1 or claim 2, wherein plasticizer (f) is a polysiloxane compound, a fatty acid condensation product or their mixture.
 10. A carpet treated by depositing on it an amount of the composition of claim 1 or claim 2 which is effective to impart resistance to staining.
 11. The treated carpet of claim 10 wherein the deposition is achieved by a foam-co-application.
 12. The treated carpet of claim 10 wherein said effective amount is between 0.5 and 5% by weight of the carpet.
 13. The treated carpet of claim 12 wherein said effective amount is between 0.5 and 2% by weight of the carpet.
 14. The treated carpet of claim 10 wherein the carpet is made from a polyamide selected from the group consisting of nylon 6, nylon 6,6, wool, or a mixture of thereof.
 15. The treated carpet of claim 10 wherein the carpet is made from a nylon fiber. 